1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_GENERIC_BUG_H 3 #define _ASM_GENERIC_BUG_H 4 5 #include <linux/compiler.h> 6 7 #define CUT_HERE "------------[ cut here ]------------\n" 8 9 #ifdef CONFIG_GENERIC_BUG 10 #define BUGFLAG_WARNING (1 << 0) 11 #define BUGFLAG_ONCE (1 << 1) 12 #define BUGFLAG_DONE (1 << 2) 13 #define BUGFLAG_TAINT(taint) ((taint) << 8) 14 #define BUG_GET_TAINT(bug) ((bug)->flags >> 8) 15 #endif 16 17 #ifndef __ASSEMBLY__ 18 #include <linux/kernel.h> 19 20 #ifdef CONFIG_BUG 21 22 #ifdef CONFIG_GENERIC_BUG 23 struct bug_entry { 24 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS 25 unsigned long bug_addr; 26 #else 27 signed int bug_addr_disp; 28 #endif 29 #ifdef CONFIG_DEBUG_BUGVERBOSE 30 #ifndef CONFIG_GENERIC_BUG_RELATIVE_POINTERS 31 const char *file; 32 #else 33 signed int file_disp; 34 #endif 35 unsigned short line; 36 #endif 37 unsigned short flags; 38 }; 39 #endif /* CONFIG_GENERIC_BUG */ 40 41 /* 42 * Don't use BUG() or BUG_ON() unless there's really no way out; one 43 * example might be detecting data structure corruption in the middle 44 * of an operation that can't be backed out of. If the (sub)system 45 * can somehow continue operating, perhaps with reduced functionality, 46 * it's probably not BUG-worthy. 47 * 48 * If you're tempted to BUG(), think again: is completely giving up 49 * really the *only* solution? There are usually better options, where 50 * users don't need to reboot ASAP and can mostly shut down cleanly. 51 */ 52 #ifndef HAVE_ARCH_BUG 53 #define BUG() do { \ 54 printk("BUG: failure at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \ 55 barrier_before_unreachable(); \ 56 panic("BUG!"); \ 57 } while (0) 58 #endif 59 60 #ifndef HAVE_ARCH_BUG_ON 61 #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0) 62 #endif 63 64 #ifdef __WARN_FLAGS 65 #define __WARN_TAINT(taint) __WARN_FLAGS(BUGFLAG_TAINT(taint)) 66 #define __WARN_ONCE_TAINT(taint) __WARN_FLAGS(BUGFLAG_ONCE|BUGFLAG_TAINT(taint)) 67 68 #define WARN_ON_ONCE(condition) ({ \ 69 int __ret_warn_on = !!(condition); \ 70 if (unlikely(__ret_warn_on)) \ 71 __WARN_ONCE_TAINT(TAINT_WARN); \ 72 unlikely(__ret_warn_on); \ 73 }) 74 #endif 75 76 /* 77 * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report 78 * significant kernel issues that need prompt attention if they should ever 79 * appear at runtime. 80 * 81 * Do not use these macros when checking for invalid external inputs 82 * (e.g. invalid system call arguments, or invalid data coming from 83 * network/devices), and on transient conditions like ENOMEM or EAGAIN. 84 * These macros should be used for recoverable kernel issues only. 85 * For invalid external inputs, transient conditions, etc use 86 * pr_err[_once/_ratelimited]() followed by dump_stack(), if necessary. 87 * Do not include "BUG"/"WARNING" in format strings manually to make these 88 * conditions distinguishable from kernel issues. 89 * 90 * Use the versions with printk format strings to provide better diagnostics. 91 */ 92 #ifndef __WARN_TAINT 93 extern __printf(3, 4) 94 void warn_slowpath_fmt(const char *file, const int line, 95 const char *fmt, ...); 96 extern __printf(4, 5) 97 void warn_slowpath_fmt_taint(const char *file, const int line, unsigned taint, 98 const char *fmt, ...); 99 extern void warn_slowpath_null(const char *file, const int line); 100 #define WANT_WARN_ON_SLOWPATH 101 #define __WARN() warn_slowpath_null(__FILE__, __LINE__) 102 #define __WARN_printf(arg...) warn_slowpath_fmt(__FILE__, __LINE__, arg) 103 #define __WARN_printf_taint(taint, arg...) \ 104 warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg) 105 #else 106 extern __printf(1, 2) void __warn_printk(const char *fmt, ...); 107 #define __WARN() __WARN_TAINT(TAINT_WARN) 108 #define __WARN_printf(arg...) do { __warn_printk(arg); __WARN(); } while (0) 109 #define __WARN_printf_taint(taint, arg...) \ 110 do { __warn_printk(arg); __WARN_TAINT(taint); } while (0) 111 #endif 112 113 /* used internally by panic.c */ 114 struct warn_args; 115 struct pt_regs; 116 117 void __warn(const char *file, int line, void *caller, unsigned taint, 118 struct pt_regs *regs, struct warn_args *args); 119 120 #ifndef WARN_ON 121 #define WARN_ON(condition) ({ \ 122 int __ret_warn_on = !!(condition); \ 123 if (unlikely(__ret_warn_on)) \ 124 __WARN(); \ 125 unlikely(__ret_warn_on); \ 126 }) 127 #endif 128 129 #ifndef WARN 130 #define WARN(condition, format...) ({ \ 131 int __ret_warn_on = !!(condition); \ 132 if (unlikely(__ret_warn_on)) \ 133 __WARN_printf(format); \ 134 unlikely(__ret_warn_on); \ 135 }) 136 #endif 137 138 #define WARN_TAINT(condition, taint, format...) ({ \ 139 int __ret_warn_on = !!(condition); \ 140 if (unlikely(__ret_warn_on)) \ 141 __WARN_printf_taint(taint, format); \ 142 unlikely(__ret_warn_on); \ 143 }) 144 145 #ifndef WARN_ON_ONCE 146 #define WARN_ON_ONCE(condition) ({ \ 147 static bool __section(.data.once) __warned; \ 148 int __ret_warn_once = !!(condition); \ 149 \ 150 if (unlikely(__ret_warn_once && !__warned)) { \ 151 __warned = true; \ 152 WARN_ON(1); \ 153 } \ 154 unlikely(__ret_warn_once); \ 155 }) 156 #endif 157 158 #define WARN_ONCE(condition, format...) ({ \ 159 static bool __section(.data.once) __warned; \ 160 int __ret_warn_once = !!(condition); \ 161 \ 162 if (unlikely(__ret_warn_once && !__warned)) { \ 163 __warned = true; \ 164 WARN(1, format); \ 165 } \ 166 unlikely(__ret_warn_once); \ 167 }) 168 169 #define WARN_TAINT_ONCE(condition, taint, format...) ({ \ 170 static bool __section(.data.once) __warned; \ 171 int __ret_warn_once = !!(condition); \ 172 \ 173 if (unlikely(__ret_warn_once && !__warned)) { \ 174 __warned = true; \ 175 WARN_TAINT(1, taint, format); \ 176 } \ 177 unlikely(__ret_warn_once); \ 178 }) 179 180 #else /* !CONFIG_BUG */ 181 #ifndef HAVE_ARCH_BUG 182 #define BUG() do {} while (1) 183 #endif 184 185 #ifndef HAVE_ARCH_BUG_ON 186 #define BUG_ON(condition) do { if (condition) BUG(); } while (0) 187 #endif 188 189 #ifndef HAVE_ARCH_WARN_ON 190 #define WARN_ON(condition) ({ \ 191 int __ret_warn_on = !!(condition); \ 192 unlikely(__ret_warn_on); \ 193 }) 194 #endif 195 196 #ifndef WARN 197 #define WARN(condition, format...) ({ \ 198 int __ret_warn_on = !!(condition); \ 199 no_printk(format); \ 200 unlikely(__ret_warn_on); \ 201 }) 202 #endif 203 204 #define WARN_ON_ONCE(condition) WARN_ON(condition) 205 #define WARN_ONCE(condition, format...) WARN(condition, format) 206 #define WARN_TAINT(condition, taint, format...) WARN(condition, format) 207 #define WARN_TAINT_ONCE(condition, taint, format...) WARN(condition, format) 208 209 #endif 210 211 /* 212 * WARN_ON_SMP() is for cases that the warning is either 213 * meaningless for !SMP or may even cause failures. 214 * This is usually used for cases that we have 215 * WARN_ON(!spin_is_locked(&lock)) checks, as spin_is_locked() 216 * returns 0 for uniprocessor settings. 217 * It can also be used with values that are only defined 218 * on SMP: 219 * 220 * struct foo { 221 * [...] 222 * #ifdef CONFIG_SMP 223 * int bar; 224 * #endif 225 * }; 226 * 227 * void func(struct foo *zoot) 228 * { 229 * WARN_ON_SMP(!zoot->bar); 230 * 231 * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(), 232 * and should be a nop and return false for uniprocessor. 233 * 234 * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set 235 * and x is true. 236 */ 237 #ifdef CONFIG_SMP 238 # define WARN_ON_SMP(x) WARN_ON(x) 239 #else 240 /* 241 * Use of ({0;}) because WARN_ON_SMP(x) may be used either as 242 * a stand alone line statement or as a condition in an if () 243 * statement. 244 * A simple "0" would cause gcc to give a "statement has no effect" 245 * warning. 246 */ 247 # define WARN_ON_SMP(x) ({0;}) 248 #endif 249 250 #endif /* __ASSEMBLY__ */ 251 252 #endif 253